Currently the styling on the button for the user menu in the header (and possibly elsewhere!) resets outline: none. This will also reset the outline for a focussed button element, so there will be no visual clue indicating to the user the button is focussed, thus making non-focussed and focussed states indistinguishable.
The reset of the focus should not affect the focus state, therefore the above mentioned rule should be removed completely. If this gives us a problem, we need to further discuss this, and just reset the states we actually want to reset in a more specific manner.